#include<stdio.h>
#include<unistd.h>

int main(){
  int flag = chdir("/home/ynp");
  if(flag == -1){
    perror("Chdir");
    return 1;
  }
  FILE* pf = fopen("Hello.txt", "w");
  printf("Hello\n");
  fclose(pf);
  return 0;
}
